Serious adverse drug reactions (sADRs) account for over 100,000 deaths annually. Investigation into barriers in identification and dissemination of sADR information for drugs is likely to have a direct benefit on patient safety, save lives, and identify areas for future policy changes. These considerations are especially important for cancer drugs, where the emphasis has been on accelerated FDA approval and shorter review times, raising concern that attention to sADRs may not be sufficient. In this study, we propose to describe all sADRs associated with oncology drugs that were identified between 1996 and 2003. We will conduct a comprehensive search of MedWatch (the FDA's voluntary reporting system), cooperative oncology group toxicity reports, MedLine and other electronic databases, abstracts from major health conferences, pharmacovigilance program websites from Europe, Australia, and Canada, "Dear Doctor" letters, and FDA package label revisions for all sADRs for oncology drugs and compile and report complete case series information on each of these sADRs. Our preliminary analyses suggest that we will identify between 80 and 100 sADRs in our search. We will also describe dissemination efforts for the sADRs and identify the relevant milestones related to identification and dissemination of each sADR. These milestones include: the date of New Drug Application (NDA), date of submission of clinical packet for consideration of FDA approval, date of FDA approval, date of reporting of the first sADR to the FDA, date of reporting of the 10th case to the FDA, and date for which a comprehensive case series was developed and reported in the peer-reviewed literature, Dear Doctor letters, and package inserts. Additionally, we will assess the relationship between time from initial application for FDA approval to identification and reporting of the sADRs as a group and of several individual sADR characteristics. Our preliminary studies indicate that only 30% of previously unreported sADRs identified in the past five years have been described in the literature, and for the reported sADRs, dissemination efforts were often delayed. The findings of this study would: 1) provide more comprehensive and current information about sADRs associated with cancer drugs and 2) provide the first set of empirical data on barriers to identification and reporting of these important clinical events.